There is Something New under the Sun: Materials for New Solar Cells

Arie Zaban, Department of Chemistry, Bar Ilan University, Ramat-Gan , Israel

Photovoltaics (PVs) installation around the globe approached 180GW by the end of 2014, with annual growth of 45GW. Maintaining the current growth rate will enable more than 400GW installed by 2018 with an annual growth rate of approx. 55GW. These numbers represent a dramatic decrease in module and installation cost which lead to grid parity, the holy grail of renewable energy. Though dominated by silicon based systems, PV research seeks new systems that beyond low cost will involve low energy of production, earth abandon materials and longer service life.

Starting at 2011, organic-inorganic halide perovskites have emerged as one of the most promising competitors to silicon-based PVs. This is enabled by the unique properties of this earth-abundant family of materials which are processed at very low temperatures yielding high power conversion efficiency (>20%), though still challenged by stability issues. Following the same design rules, another PV family which is solely based on metal oxides is showing promising results. Here also, the raw materials are earth abandon, the fabrication process is of low cost and the higher conversion efficiencies involve perovskite crystals as solar absorbers. Encouraged by the intrinsic stability of metal oxide based systems these cells have reached 8.1% conversion efficiency.

Possible connection between the two advancing systems will be examined, discussing materials discovery, perovskite properties and devices mechanisms.